Spinal surgeries that require implantation of devices into intervertebral spaces are well known. In order to determine an appropriate size intervertebral implant, it may be necessary to use tools to measure the intervertebral space. Currently used tools may include tools that include snap-on heads of varying size that are switched out until the appropriate diameter across the intervertebral space is determined. Alternatively, a number of different tools, each of different size, may be used.